. >> i just had a colonoscopy at a local hospital. before they put me under, they made me sign that everybody in the room washed their hands and i had seen them wash their hands. this is something to attack. >> being a physician and learning surgery and the five minute scrub, that's what we typically do. the average american does not wash their hands for, they say between 40 seconds to 60 seconds. >> you'll tell us how long to do it and how to tell. >> yes. >> let's look at a slide you brought with you of an unwashed hand. see if we have that with us. tell us what we are looking at. >> a dirty hand. after 24 hours of incubation, this is the growth you see. >> what is it? >> bacterial colonies. i reproduced this in my office, put on gloves and touched doorknobs and brought my cultures in after 24 hours. you can see that with a gloved hand, even though you think the person is sterile, if they are touching things, it can transmit bacteria. >> look at that. >> this is just in 24 hours. i had gloves on, just touching doorknobs. this is act